We've forgotten where we came from.
I fly radio control planes, I started out with Sanyo SCR600 cells, that lasted maybe 4minutes, and now in the same airframe I have managed to stay aloft 42mins using lipo batteries, with 4x the capacity, 1.5x the voltage and 2/3 the weight.
The early lipo cells could barely pump out 10A, anyone remember 2s3p batteries? And now I can draw nearly 50amps from a pack the same physical size, and charge it in half the time.
Battery performance has greatly improved, we are just looking at the wrong measure of improvement.